The Economic Way of Thinking 13th Edition by David Prychitko, Peter Boettke, Paul Heyne

Exercise 21

The supply curve on the graph in Figure 4-4 shows the wage rates that would have to be offered by business firms to obtain various quantities of hours of envelope stuffing on any given day.
(a) What wage rate will firms have to offer if they want to hire 400 hours of envelope stuffing?
(b) What will be the firms' total expenditure on the wages of envelope stuffers?
(c) What will be the total opportunity cost to the envelope stuffers of stuffing envelopes? ( Hint : Each square represents $20: 20 hours times $1.)
(d) What is the price elasticity of supply between $4 and $6? Between $6 and $8?